In 2009 alone, the Lafarge North America cement plant in Bath, Ontario, completed a range of environmental and energy efficiency projects. The multitude of projects proved the Canadian plant worthy of earning the Overall Environmental Performance Award for the Ninth Annual Cement Industry Energy & Environmental Awards, presented by the Portland Cement Association (PCA) and Cement Americas.

The Energy Farm Initiative

As part of its climate change and energy efficiency programs, Lafarge Bath began working with Queen’s University researchers on its “Energy Farm” initiative, in which a variety of plant species and crops are grown onsite that could eventually be used as renewable biomass sources. The project, with additional support from Wildlife Habitat Council biologists, will determine the effectiveness of purpose-grown biomass fuels in the plant’s cement kiln.

To determine which crops are best suited to growing in the area, the Energy Farm team planted three potential crops in four fields on the plant grounds. Each field was divided into four strips, with each crop planted in one strip, and one strip left fallow. As these are perennial crops, data will be gathered over several years before conclusions may be drawn.

Another component of the Energy Farm project is a perimeter of native grass and wildflower species planted around each of the fields used for the project. In addition to combating the typical soil erosion associated with cultivated land, these borders will provide pollinator habitat.

This work also plays a role in the Life Cycle Assessment (LCA) program preformed in conjunction with Queen’s University and the Ontario Ministry of the Environment. The LCA study will determine the net carbon savings from the use of purpose-grown biomass crops as a replacement for coal, as well as various land use questions and water consumption.

Lafarge Bath also worked with area farmers to raise crops for a trial biomass burn. Farmers produced crops such as hemp, sorghum, canary grass, millet, tropical corn, and switchgrass on small, local farms before shipping them to the plant for storage. More than 950 bales of plant material have been collected for the biomass trial planned for 2010.

 Exploring Experimental Renewable Energy Sources

Lafarge Bath is working with the Queen’s University’s Biology Department on a real-world laboratory approach to willow genetic development. The plant has provided land and preparation services to Dr. Sharon Regan’s willow development work wherein over 100 novel, hybridized willow species have been transplanted from the university’s greenhouse to a field on Lafarge property. These species will be monitored for enhanced traits such as disease resistance, biomass production rate and drought resistance.

The plant is also studying, through Queen’s University and Canadian Wollastonite, the potential for the use of wollastonite and diopside as carbon sequestration solutions. The concept is to take these typically rare minerals, which are available in great quantity in a newly discovered nearby wollastonite quarry, dissolve them in a weak acid solution, and allow them to react with kiln stack gases to form two products with commercial value, while sequestering carbon dioxide, mercury, and sulphur dioxide.

Yet another part of the biomass fuels project, the plant has been working with a group of mechanical engineering students on an analysis of the potential use of torrefaction to process raw biomass. The aim is to produce a stable, coal-like fuel product with a high calorific value that could be entirely substituted for coal.

 Promoting Habitat Restoration

With the help of 250 local scouts, leaders, and parents, Lafarge Bath planted 3,000 trees on its property for habitat restoration and climate change education and mitigation.

Also in 2009, several areas around the plant, which have historically been maintained as lawns, have been deliberately left untended, allowing native plant species to retake the area. This has resulted in wildflower meadows where many varieties of birds and butterflies reside.

The Bath plant is certified in the Wildlife Habitat Council’s “Wildlife at Work” program. This certification was granted for a variety of projects including the planting of forage plots for larger mammals living onsite, and a monitoring program, in which employees track wildlife seen in various areas around the site.

Employees do much of the work required to maintain this program on their own time, underscoring their deep, personal commitment to environmental stewardship.

Reducing and Reusing Cement Kiln Dust

The installation of new, axial blower technology allows Lafarge Bath to reuse cement kiln dust (CKD) and optimize fuel consumption through improved process stability, thereby further reducing CO₂ emissions.

With additional kiln operation and quarry changes, the facility has nearly eliminated CKD production. The plant was able to reach a 90% reduction in CKD landfilling in 2009 as compared to 2008. Likewise, the CKD monofills were improved because little to no CKD will be produced in the future.

The plant installed additional equipment in 2009 that will eliminate the remaining 10% of CKD landfilling and the plant expects that it will no longer landfill CKD as a result. The modifications allow the plant to temporarily store CKD generated during initial start-up periods and to then reintroduce it either as limestone additions or to return it as raw material.

Energy Saving and Intensity Applications

The installation of the axial blower technology has also allowed Lafarge Bath to improve kiln operation and increase its utilization of petroleum coke (pet coke). Petcoke is a common type of alternative fuel derived as a byproduct of refining operations; its usage increases energy efficiency due to its high calorific value.

It is anticipated that sulfur and carbon dioxide emissions will lower as well as fuel consumption with the new blower system. This technology also allows for improved chlorine and sulfur trapping. 

The plant started a wet sand trial for its raw mix in 2009. Wet sand allows the plant to run the natural gas powered sand dryer on a limited basis, typically during colder weather. This trial proved successful, and the practice of using wet sand in the raw mix will be continued into 2010.

The plant also started a cogeneration, pre-feasibility study aimed at installing a system to capture waste heat from the kiln and use it to generate electricity. Through capture of waste heat, the plant could produce 6-8 megawatts of power. At this time, the project is in its earliest stages, and is intended to be ready for implementation in the next 3-5 years.

The possible addition of a biomass supplemental boiler has been identified. Combined with the heat recovery unit, the biomass unit could provide nearly all of the plant’s electricity.

Leading a New Era of Environmental Policy

A new era of environmental policy is emerging in Ontario. The Province is in the midst of redeveloping guidelines and policies. The Bath plant is the most knowledgeable industrial player in the province and has taken a leading role in blazing the trail for future permitting efforts in Ontario.

Specifically, Lafarge’s Bath plant produced a first of its kind permit application that directly addressed cumulative effects, the precautionary principle, the public right to know, and many other foundational elements of the Province’s Statement of Environmental Values. Lafarge’s permitting strategy has set the pace and the foundation for future permit applications.

The plant has played a key role in information gathering to support the Government of Canada's Chemicals Management Plan. The federal program challenges industry to identify selected toxic compounds in their raw materials, fuels, and products and to identify means of reducing public risk from their use.